Refrigeration apparatus



April 17, 1934. w 1,955,186

' REFRIGERATION APPARATUS Filed Aug. 2, 1929 Patented Apr. 17, 1934UNITED STATES PATENT OFFICE REFRIGERATION APPARATUS John W. Hill,Milwaukee, Wis assignor of onehalf to Fred A. Parsons. Milwaukee, Wis.

This invention relates to improvements in the art of refrigeration.

It is an object of the invention to provide a refrigerated table onwhich foods requiring refrigeration can be displayed in the open wherethey will be directly accessible without. requiring the opening ofdoors.

In making retail sales of food products and particularly in making suchsales in self-service l0 stores considerable difficulty has heretoforebeen experienced in connection with products requiring refrigeration.The repeated opening of the door in a refrigerator involves extensiveintroduction of heat into the refrigerator due to air currents set up bythe movement of the door itself. When the door is opened a large body ofair is drawn by the door out of the refrigerator and this body of air isreplaced by warm air entering the refrigerator. This constant exchangeof air created by movements of the door makes refrigeration veryuncertain and expensive under all circumstances where access must oftenbe had to refrigerated articles enclosed by a door.

The success of the self-service store is founded upon easy access to thegoods exposed for sale. It is well known by those conducting such storesthat there is a relatively very high sales resistance in connection withgoods shut up in the ordinary refrigerator. Customers are reluctant 30to open the door of the refrigerator themselves and usually ask the helpof the attendant when refrigerated articles are desired.

It is a purpose of the present invention to provide refrigeration or arefrigerator in a form to substantially remove both of the diflicultiesabove described.

It is also my object to accomplish the feature of direct accessibilityof the refrigerator con tents with less ingress of heat than would beachieved under like conditions of extensive use by the ordinarydoor-equipped refrigerator.

But where the contents of a refrigerator may remain undisturbed forconsiderable intervals as for instance in the storage of a stock ofmaterials to be drawn upon for display and sale in the refrigeratormentioned above, it is probably more economical to refrigerate suchstock in the usual types of refrigerators with well insulated doors. Atleast it is more economical in the matter of original cost and floorspace.

Another object is, therefore, to combine a refrigerator or unit such aspreviously described with another refrigerator or unit having doors,

' whereby such other unit may be housed or po- 55 sitioned in spaceotherwise wasted, and preferably underneath the refrigerator or unitpreviously described.

Another object is generally to simplify and improve the construction andoperation of refrigerators, particularly refrigerators for easy accessi-30 bility of contents, and still other objects will be apparent from thespecification.

The invention consists in the construction and combination of elementsherein illustrated, described and claimed, and in such modificationsthereof as may be equivalent to the claims.

In the drawing:

Figure 1 is a longitudinal vertical section through a. refrigeratedtable made in accordance with this invention.

Figure 2 is a. perspective view of the table on a slightly reducedscale.

Like parts are identified by the same reference characters throughoutthe several views.

An upper compartment 5 comprises a shallow 15 box supported at asuitable level about the floor and provided across its bottom 6 and itssides 7 with suitable insulation. The sides are of uniform height toprovide a substantially horizontal upper opening. go

The box is provided with spaced lining walls 8 and 9 between which therefrigerating coils 10 are disposed. Instead of being concentrated inone corner of the refrigerated compartment as is the case with'astandard refrigerator the 35 coils 10 in the present device aredistributed substantially to encircle the periphery of the refrigeratedcompartment and also substantially to cover the bottom thereof. Sucharrangement of coils provides substantially uniform refrigeration forboth the sides and bottom of the upper compartment 5 and is extremelydesirable in order to minimize or eliminate convection currents causedby unequal temperatures. It will be obvious that if any circulation ofair were established within the compartment some of the circulating airwould be projected through the open top and replacement air would bedrawn in from above.

As above indicated the upper margin of the box is preferably horizontal.A finish that is attractive and at the same time serves the purposes ofthis invention is provided by a marginal plate of glass shown at 15which extends around the perimeter of the box and overhangs the wallsthereof .to some extent to reduce the size of the opening. These plates15 assist in establishing a cleavage plane between the cold air which isheld by gravity within the box 5 and the warmer air at room temperatureswhich lies thereabove, 11

Co-operating with plates 15 in establishing a cleavage plane and inreducing themes. of the horizontal opening, I preferably employ a plate16 supported on posts 17 in the same horizontal plane as the marginalplates 15. If desired these posts may be carried up to support a displayshelf 18 and suitable lighting fixtures for the illumination of thecontents of the refrigerator.

Plate 16 has also another function. with certain food stuff it ispreferable that no dust be permitted to settle thereon. Such food may bepositioned underneath the plate 16 which then serves as a protectionagainst dust. The marginal plates 15 also answer the same purpose, butwith somewhat less favorable position of the food for display purposesand for accessibility from both sides of the box.

Beneath the compartment 5, I provide a compartment 19 for therefrigerating unit 20 and a storage refrigerator 21, which may beprovided at one end with the usual form of expansion coil 22 and at theother end with an ordinary closure such as a door 21A, preferablyhinged. There is thus provided unitarily with the special purpose box 5a considerable refrigerated space which may be used for any desiredpurposes and served by the same refrigerating unit, and with no extrafloor space required.

In operation the bottom of the refrigerated box 5 receives the articleto be kept refrigerated and at the same time exposed for sale.Ordinarily any article in the box. will not only be visible but directlyaccessible without moving other articles therein. A degree ofaccessibility is obtained which cannot exist in any other type ofrefrigerator.

The air within the box 5, being chilled, has a higher specific gravitythan the warm air on the outside and hence, because of the uniformheight of the walls of the box, is held within the box, the plates 15and 16 materially assisting in such effect. Heat transfer through thesides and bottom of the box is substantially prevented by theinsulation. The operation of this unit is, therefore, exceptionallyefficient both for cost of operation and in providing refrigerationthroughout the interior of the box at the desired temperature. I

It is, of course, understood that the'box will not be subjected toextraordinary air currents such, for instance, as might be induced by anelectric fan immediately above the box. Ordinary drafts are cared for ina satisfactory manner by the plane surfaces 15 and 16 which establish acleavage plane across which currents of air can move horizontallywithout creating any material circulation of air within the box orbetween the box and the air overlying it.

As an instance of the result obtained from the method of refrigerationutilized in the box 5, it may be stated that with a room temperature ofF. a temperature difference of only four degrees has been observedbetween top and bottom of compartment 5 during normal continuous use ofthe device, the temperature being maintained at 36 F. at the bottom ofthe box and at 40 F. at a point just below the plane defined by plates15 and 16. The entire temperature drop between room temperatures andthose existing in the box 5 is accomplished very sharply at the zonede-' fined by the plane of plates 15 and 16.

It is to be noted that for the box 21 the refrigeration is localizedwhereby a continuous circulation of moving air is induced. For acompletely enclosed box this type of refrigeration is believedpreferable. For the box 5, however, the refrigeration is distributed tothe greatest practicable extent whereby circulation or movement of airis substantially eliminated. There is thus provided a unitarycombination of two boxes each provided with a fundamentally differenttype of refrigeration best adapted for the purposes to be met, andtogether particularly adapted both for the storage of a considerablevolume of reserve food stuff, and for the accessible display of other 85food stuff for immediate sale.

. I claim:

1. A refrigerator comprising a box closed at its sides and bottom andcontinuously open at its top, and refrigerating means within the boxuniformly distributed to avoid the creation of convection currents, saidbox being provided at its upper margins with overhanging ledge means forprotecting the air withinthe box from disturbances originating in theair outside thereof and the interior of the box being free ofmechanically operated parts whereby the air therein is retainedquiescent.

2. A refrigerator comprising the combination with a box, ofrefrigerating means distributed about said box to maintain substantiallyuniform temperatures at all sides thereof whereby to avoid convectioncurrents therein, said box being continuously open at its top andadapted to retain solely by gravity the air refrigerated therein,together with substantially planiform means continuous about the top ofthe box overhanging the sides thereof for establishing a substantiallyhorizontal cleavage plane between air in said box and extraneous air allof the mechanism for the operation of said refrigerator being outside ofsaid box whereby air in the interior of said box is kept quiescent.

3. A refrigerator comprising the combination with a box, ofrefrigerating means distributed about said box to maintain substantiallyuniform temperatures at all sides thereof whereby to avoid convectioncurrents therein, said box being continuously open 'at its top andadapted to retain solely by gravity the air refrigerated therein, 12together with means at the top of the box for establishing asubstantially horizontal cleavage plane between air in said box andextraneous air, said means inwardly overhanging the box whereby to limitthe area of the opening in the top of the box.

4. A refrigerator comprising the combination with a box closed at itsbottom and having sides of substantially uniform height, ofrefrigerating means distributed about said box and adapted 136 tomaintain substantially uniform temperatures at all sides thereof wherebyto minimize convection currents therein, and plate means extending aboutthe upper margin of the box and overhanging the sides thereof, said boxbeing continuously open at its top, internally free of air disturbingmovable parts, and adapted to retain quiescent refrigerated air thereinby gravity.

5. A box having refrigerating means extending substantially continuouslyabout its sides and 1.43 having its sides finished at substantially thesame horizontal plane at their upper margins in combination with a platedisposed substantially in said plane and spaced between said marginswhereby to afford a continuously open space at the top of the boxthrough which its contents are accessible.

6. A refrigerator comprising a boxprovided with uniformly distributedrefrigerating means and having closed bottom and side wall portions ofsubstantially uniform depth and'a continuously open top in combinationwith centrally disposed,

' a means for restricting the area oi. the opening in the top and fordefining a plane of cleavage between reirigerated air in the box andextraneous air.

7-. A refrigerator comprising a box provided with refrigerating meansand having closed bot* tom and sidewall portions and a continuously opentop, in combination with means for restrictin: the area oi'the openingin the top and for de-

